Device for connecting bus bars

ABSTRACT

A device for connecting bus bars comprising a body made of conducting material which has three elements which lie along three substantially mutually perpendicular planes, of which: 
     a first flat base element has a first outer side and a second outer side which are arranged in an L-shaped configuration with respect to each other, a third inner side and a fourth inner side being arranged in an L-shaped configuration with respect to each other and being substantially parallel to the corresponding outer sides; 
     a second flat element is arranged along said first outer side of the first element; 
     a third flat element is arranged along said second outer side or along said fourth inner side of the first element, the second flat element and the third flat element having such a length that their minimum relative distances allow the free passage of the bars, said first, second and third flat elements being further provided with a plurality of slots suitable to receive means for connection to the bars.

BACKGROUND OF THE INVENTION

The present invention relates to a device for connecting bus bars havingimproved shape and characteristics.

More particularly, the connecting device according to the invention hasa structure which allows to connect bus bars having any shape, be theyvariously shaped or flat, and with any connection configuration, beingunique with respect to conventional devices owing to its extremeflexibility in use and to the simplicity of its production and assembly.

It is known that electric power distribution switchboards use, in orderto distribute electric power to a plurality of electrical devices, suchas for example circuit breakers, a system of mutually parallel metalbars which are arranged in an aligned or staggered configuration.

Each one of said bars is connected to a corresponding polarity of theelectric power supply mains; the connection between the bus bars and thedevices is provided by means of suitable conductors, such as for examplelaminae, which are shaped appropriately according to the type of device.

Inside the cabinets that accommodate the distribution switchboards, theconfiguration of the switchboards can be highly variable according tothe different application requirements: thus, for example, the devicesto which the bus bars are to be connected can vary in terms of type,shape and position; accordingly, the positions of the bars and thecorresponding connection configurations to be provided are alsoextremely variable.

For example, two bars may be connected at right angles or in a T-shapedconfiguration or in other configurations, or a plurality of secondarybars may be connected along the entire extension of a same main bus barwhich passes through one or more side-by-side cabinets.

In the current state of the art, these connections among bus bars areprovided by virtue of connecting devices which have some drawbacks.

In particular, the main shortcoming of conventional connecting devicesis their limited flexibility in use. If the mutual arrangement of thebus bars and their shape change, it is necessary to adopt differentlyshaped connecting devices, with consequent negative effects onproduction costs and on assembly difficulties.

An example in this regard is given by U.S. Pat. No. 5,364,203, whichdiscloses a device for connecting two flat bus bars by means of anappropriately configured damper which is connected to the bars by meansof bolts and nuts. Furthermore, the illustrated solution provides forbending the end portion of one of the two bars so as to surroundlaterally the other one and avoid any lateral shift thereof.

Although this solution is effective in the case of flat bars, it isentirely inapplicable to bars having different shapes andconfigurations; furthermore, the need to produce a hole in the bus barsand to bend them complicates production without significantlysimplifying assembly in return. The fact should also be noted that whenthe bars to be connected conduct currents which have differentamperages, the surface of contact between the connecting device and thebus bars must be sufficient to ensure correct and efficient conductionof the current between the bars. In the current state of the art,conventional devices are not suitable to universally connect the busbars to each other, so that depending on the amperage levels involved itis necessary to adapt the dimensions of the devices to the specificpractical application, entailing a consequent increase in productioncosts.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a device for connectingbus bars which is extremely flexible in use and allows, in particular,to connect bars having different shapes and with any mutual connectingarrangement.

Within the scope of this aim, an object of the present invention is toprovide a device for connecting bus bars which is easy to manufactureand allows to significantly simplify the steps for connecting the busbars inside electrical distribution switchboards.

Another object of the present invention is to provide a device forconnecting bus bars which is capable of efficiently connecting bars thatcarry currents whose amperages are even considerably different from eachother without having to modify the dimensions of said connecting device.

Another object of the present invention is to provide a device forconnecting bus bars which is highly reliable, relatively easy tomanufacture and at competitive costs.

This aim, these objects and others which will become apparenthereinafter are achieved by a device for connecting bus bars,characterized in that it comprises a body made of conducting materialwhich has three elements which lie along three substantially mutuallyperpendicular planes, of which:

a first flat base element has a first outer side and a second outer sidewhich are arranged in an L-shaped configuration with respect to eachother, a third inner side and a fourth inner side being arranged in anL-shaped configuration with respect to each other and beingsubstantially parallel to the corresponding outer sides;

a second flat element is arranged along said first outer side of thefirst element;

a third flat element is arranged along said second outer side or alongsaid fourth inner side of the first element, the second flat element andthe third flat element having such a length that their minimum relativedistances allow the free passage of the bars, said first, second andthird flat elements being further provided with a plurality of slotssuitable to receive means for connection to the bars.

The connecting device according to the invention has the considerableadvantage of allowing the connection of bus bars of any kind and shape,even flat ones; furthermore, the structure of the connecting deviceallows to connect the bus bars very simply and effectively, regardlessof the bar connection configuration to be obtained and regardless oftheir arrangement inside the cabinets of the distribution switchboards.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will becomeapparent from the description of preferred but not exclusive embodimentsof the connecting device according to the invention, illustrated only byway of non-limitative example in the accompanying drawings, wherein:

FIG. 1 is a perspective view of a first preferred embodiment of theconnecting device according to the invention;

FIG. 2 is a top plan view of the connecting device of FIG. 1;

FIG. 3 is a perspective view of a second embodiment of the connectingdevice according to the invention;

FIG. 4 is a top plan view of the connecting device of FIG. 3;

FIG. 5 is a perspective view of a third embodiment of the connectingdevice according to the invention;

FIG. 6 is a perspective view of a fourth embodiment of the connectingdevice according to the invention;

FIG. 7 is a perspective view of a connection between shaped bus bars bymeans of the connecting device of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the above Figures, the connecting device according tothe invention, generally designated by the reference numeral 100, isconstituted by a single body made of conducting material, for examplecopper, which comprises three elements which lie on three main planes.In particular, as shown in detail in FIG. 2, the connecting device 100has a first flat base element 1 which has a first outer side 2 and asecond outer side 3, which are arranged in an L-shaped configurationwith respect to each other, and a third inner side 4 and a fourth innerside 5, which are arranged in an L-shaped configuration with respect toeach other and are substantially parallel to the corresponding outersides 2 and 3.

As shown in FIG. 2, the pairs constituted by the outer side 2 and theinner side 4 and by the outer side 3 and the inner side 5 are mutuallyconnected respectively by the sides 8 and 9 that form the remainingperimetric portion of the flat base element 1.

A second flat element 6 and a third flat element 7 protrude from thebase element 1 and are arranged so that the three flat elements 1, 6 and7 are substantially perpendicular to each other. As shown in FIGS. 1 and2, in a preferred embodiment of the connecting device according to theinvention each one of the two flat elements 6 and 7 is arranged along acorresponding outer side, respectively 2 and 3, of the base element 1;in particular, the second flat element 6 and the third flat element 7are arranged respectively at one end of the first outer side 2 and ofthe second outer side 3. Moreover, the flat elements 6 and 7 haveidentical lengths 10 and 12 thanks to which their mutual distances f andf′ allow the free passage of the bars to be connected. The mutualdistances f and f′ are to be understood respectively as the distancebetween the end 41 of the element 6 and the plane on which said element7 lies, and as the distance between the end 42 of the element 7 and theplane on which the element 6 lies.

As an alternative, the lengths of the two flat elements 6 and 7 may alsobe mutually different, so long as the distances f and f′ still allow thebars to pass freely.

This allows to have a structure of the connecting device which iscompact in shape and extremely effective in application; the outsideperimeter of the connecting device at the corner region 40 is in factfree from lateral protrusions and allows the bars to be connected toslide in both of the directions defined by the axes 20 and 30. In thismanner it is possible, for example, to connect the bus bars in avertical, horizontal or inverted T-shaped configuration, in aright-angled configuration etc., and in any position along theirlongitudinal extension.

Advantageously, the three flat elements 1, 6 and 7 also have a pluralityof slots 11 which allow connection between the connecting device and thebus bars thanks to adapted fixing means, such as for example bolts. Theslots have a U-shaped profile and are conveniently located on thesurface of the three elements so as to ensure extreme flexibility in theposition for fixing with respect to the bars. For example, the baseelement 1 comprises three U-shaped slots 11: two are arranged along thesame axis 20 with oppositely orientated profiles and a third one isarranged along an axis 30 which is perpendicular to the axis of thefirst two, while the two planes 6 and 7 comprise one slot each. Thisarrangement is obviously to be understood merely as an example, sincethe shape, the dimensions, the number and the arrangement of theU-shaped slots, as well as the dimensions of the three flat elements 1,6 and 7, may be any according to the applications and/or according tospecific requirements; an example in this regard is shown in FIG. 6,which illustrates a fourth embodiment of the connecting device accordingto the invention.

In a second embodiment, shown in FIGS. 3 and 4, the second flat element6 and the third flat element 7 are arranged respectively at the end of afirst outer side 2 and at the end of the inner side 5 that correspondsto the second outer side 3. In this case also, the relative distancebetween the two flat elements 6 and 7 must allow the bars to passfreely.

Furthermore, the second and third flat elements 6 and 7 can be arrangedon the same half plane with respect to the base element 1, as shown inFIG. 1, or as an alternative, if required by the application, they maybe arranged on opposite half planes with respect to said base element 1,as shown in FIG. 5.

Another advantageous aspect of the connecting device according to theinvention is the fact that it can be obtained from a single die-cut andappropriately folded metal plate, being different from conventionaldevices in its extremely simple and low-cost production.

A further considerable advantage of the connecting device according tothe invention lies in the fact that its surface extension allows toincrease the regions of contact with the associated bus bars and toimprove their conducting capabilities, allowing in particular to connectbars that conduct currents whose values differ even considerably withouthaving to adopt different dimensions according to the instances ofpractical application.

In practice it has been observed that the connecting device according tothe invention fully achieves the intended aim, since it allows toprovide connections between bus bars having the most disparate shapesand with any connection configuration according to a solution which issimple, cheap and at the same time effective. An example of possibleconnection between bus bars is shown in FIG. 7, in which two shaped bars200 and 300 are mutually coupled in a T-shaped configuration by means ofa connecting device 100; the connecting device and the bars are thenmutually fixed thanks to conventional fixing means, such as a T-shapedbolt, not shown in the Figure for the sake of simplicity inillustration.

The device according to the invention is particuraly suitable for use inelectric switchboards; in fact, electric switchboards generally comprisea plurality of electrical devices, such as circuit breakers and thelike, which are electrically connected to corresponding bus bars in amanner which is well known in the art; advantageously, the connectingdevice according to the invention can be used in order to connect acouple of bars, as previously described.

Accordingly, the present invention also relates to an electricswitchboard comprising a plurality of electrical devices, such ascircuit breakers and the like, which are electrically connected tocorresponding bus bars, characterized in that it comprises a connectingdevice according to the invention.

The connecting device thus conceived is susceptible of numerousmodifications and variations, all of which are within the scope of theinventive concept; for example, the U-shaped slots can have a differentprofile, or they can be substituted by holes. All the details mayfurthermore be replaced with other technically equivalent elements.

In practice, the materials used, so long as they are compatible with thespecific use, as well as the dimensions, may be any according to therequirements and the state of the art.

What is claimed is:
 1. A device for connecting bus bars, comprising asingle body made of conducting material which has three elements whichlie along three substantially mutually perpendicular planes, of which: afirst flat base element has a first outer side and a second outer sidewhich are arranged in an L-shaped configuration with respect to eachother, a third inner side and a fourth inner side being arranged in anL-shaped configuration with respect to each other and beingsubstantially parallel to the corresponding outer sides; a second flatelement is arranged along said first outer side of the first element; athird flat element is arranged along said second outer side or alongsaid fourth inner side of the first element, the second flat element andthe third flat element being arranged along the corresponding sides sothat their minimum relative distances, considered as the distancebetween one end of the second element and the plane on which the thirdelement lies, and the distance between one end of the third element andthe plane on which the second element lies, respectively, allow the freepassage of the bars, said first, second and third flat elements beingfurther provided with a plurality of slots suitable to receive means forconnection to the bars.
 2. The device according to claim 1, wherein thesecond flat element and the third flat element are arranged respectivelyat one end of said first outer side and of said second outer side of thefirst element.
 3. The device according to claim 1, wherein the secondflat element and the third flat element are arranged respectively at oneend of said first outer side and at one end of the fourth inner sidethat corresponds to the second outer side.
 4. The device according toclaim 1, wherein the second flat element and the third flat element arearranged on a same half plane with respect to the first flat baseelement.
 5. The device according to claim 1, wherein the second flatelement and the third flat element are arranged on opposite half planeswith respect to the first flat base element.
 6. The device according toclaim 1, wherein said slots have a U-shaped profile.
 7. The deviceaccording to claim 1, wherein the second flat element and the third flatelement have the same length.
 8. The device according to claim 1,wherein it is formed from a single die-cut and bent metal plate.
 9. Anelectric switchboard comprising a plurality of electrical devices, suchas circuit breakers and the like, which are electrically connected tocorresponding bus bars, comprising a connecting device furthercomprising a single body made of conducting material which has threeelements which lie along three substantially mutually perpendicularplanes, of which: a first flat base element has a first outer side and asecond outer side which are arranged in an L-shaped configuration withrespect to each other, a third inner side and a fourth inner side beingarranged in an L-shaped configuration with respect to each other andbeing substantially parallel to the corresponding outer sides; a secondflat element is arranged along said first outer side of the firstelement; a third flat element is arranged along said second outer sideor along said fourth inner side of the first element, the second flatelement and the third flat element being arranged along thecorresponding sides so that their minimum relative distances, consideredas the distance between one end of the second element and the plane onwhich the third element lies, and the distance between one end of thethird element and the plane on which the second element lies,respectively, allow the free passage of the bars, said first, second andthird flat elements being further provided with a plurality of slotssuitable to receive means for connection to the bars.